Black Ivory calls itself the “rarest and most expensive” coffee in the world. A statement on its website reads: “Approximately 8,800 beans are picked for each kilogram of roasted coffee; thus, 33 kilograms of coffee cherries are required to produce just one kilogram of Black Ivory Coffee.”

Similarly-produced civet coffee – also named Kopi Luwak – grew in popularity through the Noughties and a kilogram can be bought on coffee websites in packages in excess of £280.

That trade, in which cat-like Indonesian palm civets consume coffee berries, has been dogged by claims of animal abuse and a market flooded with fakes.

“Fermentation is great for things like wine or beer or coffee, because it brings out the sugar in the bean, and it helps impart the fruit from the coffee pulp into the bean,” Mr Dinkin said.

“I want people to taste the bean, not just the roast. The aroma is floral and chocolate; the taste is chocolate malt with a bit of cherry; there’s no bitterness; and it’s very soft, like tea. So it’s kind of like a cross between coffee and tea,” he added.

Black Ivory Coffee ready for sale. The coffee can be bought online at $198 for three 35-gram (1.2-ounce) packets, equivalent to $1,886 a kilogram. It can also be purchased in about 25 luxury hotels across Asia. Dinkin says he’s looking to expand into European hotels and Michelin-starred restaurants.